This invention relates generally to a rotatable locking device and, more particularly, to an assembly for use with aircraft wings which allows one section of a wing to fold by way of a hinge and to securely lock so as to prevent movement at established points within the angle of rotation.
Hinged wing fold assemblies are used, for example, with respect to military aircraft in order that multiple aircraft may be compactly stowed together. Due to the obvious space constraints aboard aircraft carriers and like vessels, foldable aircraft wing assemblies find particular utility in applications of this sort. With the advantage of gained space, however, arises a number of critical considerations pertaining to the flight readiness character and in-flight safety and navigability of aircraft having folding wings.
There exists a known prior art wing fold assembly which involves an elaborate gear train system consisting of planetary and ring gears and having integral lugs for attachment of the gear train to both the inner fixed wing component and the outer folding wing component of an aircraft having a wing fold assembly. Due to the great number of gearings in the series-arranged train assembly, the system is made entirely of steel. Driving the system requires a geared transmission also constructed of steel as well as a motor sufficiently powerful to render the system operable. While systems of this type have proven the viability of foldable wing assemblies in aircraft and, more particularly, high-performance military aircraft, these systems are afflicted with a host of significant disadvantages and shortcomings. In particular, the all-steel construction of the system presents a number of inherent problems. Steel is heavy, expensive and prone to corrosion. Moreover, the individual steel gearing components are expensive and time-consuming to produce as well as vulnerable to physical wear. Further, the geared configuration of the system fails to provide an adequate "locking" means particularly when the outer wing component is in its faired or fully extended position. While the actuated gear drive holds the foldable wing section in its extended position during flight, extreme gravitational and torsional forces are imposed upon this hinged joint by certain high-performance military aircraft often creating undesirable movement at the joint. Movement such as this is typically referred to as "back lash." An enhanced degree of stiffness or reduced back lash at the fold joint is thereby necessitated. Accordingly, the performance characteristics of various aircraft are adversely affected or limited by the known device.
Thus, the art has lacked a wing fold assembly that is comparatively light, simple in design, resistant to corrosion and reliable in service that can provide much improved joint stiffness without gears. The invention disclosed and claimed herein achieves these advantages in a manner not revealed by the prior art.